Most of the Antarctic continent is constantly covered in ice but a tiny fraction experiences snow melts during spring. This melting allows a variety of plants, animals, and other organisms to flourish in the short warmer months. But this rich biosphere is under threat.
Researchers have published a report that shows that climate change will prolong the time these areas of the continent are thawed and this will allow invasive species, more adapted to a milder climate, to easily expand in this delicate ecosystem. The work is published in Science Advances.
If the rate of warming stays the same, experts believe that the ice-free area in the Antarctic Peninsula will triple in the next 100 years. And that’s because, luckily, the southern continent is warming at a slower rate than the rest of the planet.
"Climate change both reduces the barrier to getting in, so it makes it less stressful... and it reduces the problems of establishing," British Antarctic Survey expert Peter Convey, who co-authored the research, told AFP.
One particular issue for terrestrial environments in the continent is the presence of humans. Around 5,000 people work in Antarctica and about 50,000 tourists visit it every year. These humans are actually causing some of the invasions; two species of flies managed to get to the continent thanks to us.
The team also reports that Poa annua, a grass usually found growing in temperate climates, has been able to establish small patches on some islands. The continent is 1,000 kilometers (600 miles) from South America, so the species that manage to fly or raft there are unlikely to be able to form a permanent settlement.
"The bottom line is that humans bring in 99 percent of [invasive species] and they far outweigh any natural process," said Convey.
The researchers state that over the last two centuries, 100 new species have been introduced to the continent. And that's before you take into account the impact of climate change and human activity on the marine environment around Antarctica.
“One of the founding Antarctic Treaty principles, reaffirmed in the 'Santiago Declaration' of 2016 is to ensure the preservation and protection of the Antarctic environment,” the scientists write in the report. “Antarctica faces twin challenges from the multiple consequences derived from global environmental change and more local-scale direct impacts of human activity, and both need attention if this founding principle is to be achieved.”
The team calls for the political will to commit to the protection of the southern continent and its unique biosphere.